Electrically conductive materials are used for a variety of purposes in the fabrication and assembly of electronic devices, integrated circuits, semiconductor devices, passive components, solar cells, and/or light emitting diodes.
In general, electrically conductive adhesives (ECAs) provide a mechanical bond between two surfaces and conduct electricity. Typically, ECA formulations are made of organic binder resins filled with electrically conductive metal fillers. The binder resins generally provide a mechanical bond between two substrates, while the electrically conductive fillers generally provide the desired electrical interconnection.
Typical electrically conductive adhesives require high loadings of electrically conductive fillers which are normally made from expensive conductive metals, such as silver. Silver-coated metal fillers, e.g. silver-coated copper fillers also have been developed and used in the art. However, the electrical conductivity of adhesive formulations, comprising silver-coated fillers is often significantly reduced compared with formulations based on filler materials made of silver.
Hence, there is still a need to develop new conductive fillers for electrically conductive adhesives to reduce or replace the use of expensive conductive metals, such as silver, and to provide good electrical conductivity.